go to eBay lol
Check under the forearm
Take the forearm off, it's usually on the bottom of the barrels.
J Janssen was one of the partners of Simonis, Janssen and Dumoulin which was a Belgian gunmaking firm that produced shotguns for the American hardware store trade from the late 1880's through about 1910. Value is for decoration, and rarely exceeds $250.
You could check midwayusa.com. If they don't have what you're looking for, I would suggest going to a local gunsmith.
Euro made. Get an appraisal
Remington cowboy model or Itt international both are stage coach style guns that go for about $300. Besides that there are side-by-sides offered from most of the major gun manufactures but most go for about 2k.
Janssen was a Belgian gunmaker. According to my notes, the company used this name c. 1892 - 1896. Answer I have a Janssen Sons shotgun that used to belong to my grandfather. It has carving on the side of the breech and the bottom. It also has carvings on the walnut stock. I was given this same gun from my father. It has very detailed carvings in the stock and etchings on the barrel. I have been unable to find out anything about the maker or a present day price. I have looked in many of the shotgun books. My father paid 50 cents for this gun during the depression.
To find hammers for old rabbit ear shotguns check with Dixie Gun Works
Reccomend looking at the parts listings at Gunbroker.com. Also periodicals such as "The Gun List" and Shotgun News. The Liege model is not often found, and a forearm can be difficult. Its possible that an early Citori forearm could be fitted and something to check out. Also try the Gun Parts Corporation on line.
If it is a Side by Side like my Western Long Range Gun, pop off the forearm - mine is marked in three places: the wood of the forearm, the metal of the forearm, and on the action. My Model 37 has the serial number stamped on the front of the reciever, opposite the slide for the pump. It is in the area between the magazine tube and the barrell.
Probably about $125-$150 as a mantle decoration.